What Does A Purple Alert Mean On The Highway?
Drivers right across the country will have encountered Amber Alert messages on dynamic message signs on the highway, and many states also have a Silver Alert program in place. Some now also have Purple Alert systems, and the list of participating states is growing. Florida signed a law in 2021 to implement Purple Alerts, which distribute these alerts through media outlets, emergency alerts on Android and Apple smartphones, and highway signs.
A Purple Alert can be issued in Florida if a person goes missing who is aged 18 or older and has an intellectual or developmental disability. Authorities issue alerts only when they believe the missing person is at risk of serious, immediate harm and does not meet the criteria for a Silver Alert. Missing vulnerable people with dementia or Alzheimer's do not qualify for Purple Alerts in the state, although they may qualify for a Silver Alert instead.
Similar programs are in place in Connecticut, Kansas, Maryland, Mississippi, and Rhode Island, and several other states are planning to implement Purple Alert systems soon. Missouri is set to launch Purple Alerts (also known as RJ's Law) in 2027, and Utah also has similar plans.
The exact criteria for who qualifies for a Purple Alert can vary between states. For example, vulnerable people with dementia or Alzheimer's may qualify if they go missing in Connecticut, even though they would not be eligible in Florida.
Dynamic message signs have other uses
As well as being useful for quickly disseminating information about missing vulnerable people, dynamic message signs — which can also be called changeable message signs — are useful in various other ways. Some states are using them to implement variable speed limits on certain roads, in a bid to improve safety during times of congestion or bad weather.
Drivers might previously have also seen highway signs with amusing messages, but those are set to become less frequent in the future thanks to new government guidance. The latest guidelines outlined in the Manual on Uniform Traffic Control Devices discourage operators from displaying messages that aren't necessary, and humorous messages fall into that category.
Amber Alerts are allowed to be displayed, and states with Purple Alert programs also use highway signs to broadcast messages. However, messages on those signs must be "kept as brief as possible and, when possible, direct road users to another source, such as broadcast or highway advisory radio, for detailed information about the alert," according to the latest guidance.